Automatic dishwashing compositions which provide glassware protection are well known. The use of water-soluble zinc salts, such as zinc salts of chloride, sulfate or acetate, have been disclosed for this purpose. A water-soluble zinc salt can be employed to prevent the corrosion of ceramic surfaces. Solid plates of slowly dissolving zinc metal alloys can be placed in contact with a detergent composition or low-foaming nonionic surfactant to provide corrosion protection to glassware. In fact, insoluble inorganic zinc compounds can also be employed in conjunction with a surfactant for similar purposes. Though zinc gluconate has been prepared in-situ for use in a liquid dishwashing detergent composition, there remains a need to provide a cost-effective process of preparing in-situ water-soluble zinc salts for use in suitable automatic dishwashing compositions and/or products to help prevent glassware corrosion.
It has surprisingly been found that cost effective water-soluble zinc salts may be prepared in-situ for use in automatic dishwashing compositions and/or products. These water-soluble zinc salts when prepared in-situ and combined to form a rinse aid composition provides protection from glassware corrosion during the rinse cycle and promote consumer satisfaction in automatic dishwashing results.